Carbon dioxide is a naturally occurring substance in most hydrocarbon formations. While the carbon dioxide concentration will depend on the location of the formation, carbon dioxide concentrations as high as eighty percent are common in many areas, such as West Texas. Moreover, the implementation of tertiary recovery operations, such as carbon-dioxide injection into the subterranean wellbore, can increase the carbon dioxide concentration within the produced hydrocarbons. In either case, the carbon dioxide concentration of the produced hydrocarbons may be sufficiently high to require the carbon dioxide concentration to be reduced before the hydrocarbons can be refined or further processed.
Several solutions are known for reducing the carbon dioxide concentration or “sweetening” a hydrocarbon stream. For example, amine processes, physical solvent processes, membrane processes, and carbon dioxide recovery processes have all been used to sweeten hydrocarbon streams. The processing facilities employing these hydrocarbon sweetening processes are generally sized for a specific processing capacity and hydrocarbon feed stream composition. As such, when the carbon dioxide concentration of the hydrocarbon feed stream increases or additional feedstock comes online, then an additional processing facility must be constructed to compensate for the change in hydrocarbon feed stream composition or the increased feedstock. The construction of a new processing facility is undesirable because of the substantial capital cost, operating costs, and time delay inherent in such a solution.